Hi Terry,
Hopefully you were able to find a solution to this since your post was from 2 days ago. Can you perhaps provide some clarification? Are you running multiple campaigns for your A/B testing or just one smart campaign?
In the future, I would create two campaigns for the A/B test. Then, I would create a third one for the winning subject line, filtering out those who have already received the emails. Does that help?
-Kristine